Frigga and Loki
"I fear she is even beyond me, and even if she weren't I wouldn't risk getting to her, I might alert Odin. And that wouldn't bode well." It wouldn't bode well for any of them. Least of all him. Even if it was only for a little while, she would not risk Odin finding away to imprison him again. Frigga couldn't protect him from that, or death it seemed. Though she had tried.